This application claims priority to German Patent Application DE102009037049.8 filed Aug. 13, 2009, the entirety of which is incorporated by reference herein.
This invention relates to an engine shaft of hybrid design, more particularly the low-pressure shaft or the radial shaft of a gas-turbine engine, including a fiber-composite plastic tube connected at the ends with an externally toothed power transmission element.
In order to enable high torques to be operationally safely transmitted while keeping with reduced weight and limited outer diameter of the engine shafts of gas-turbine engines, it has been proposed to make the engine shaft of a fiber-composite plastic tube, which is made essentially of carbon fibers, and load-input and load-output elements, which are made of steel and inseparably incorporated at the ends into the fiber-composite and toothed at the free outer surface. Connection between the fiber-composite material and the metallic power transmission element is provided by a conically tapering adapter formed on the latter, providing a scarf-type joint with gradual transition between a prevailing fiber area to a prevailing metallic area. For the transmission of a maximum of torsional forces via the small connecting area, pylons are formed on the outer surface of the conical adapter at which the fibers are re-directed and routed according to the fiber orientation in the fiber-composite material.